Sample storage equipment

Abstract

This invention relates to a method for cooling and storing a sample. The programmed cooling method is divided into several step-by-step cooling methods corresponding to a standard ambient cooling curve. In each step-by-step cooling, it is determined whether the sample needs to be raised or lowered by determining whether the actual ambient temperature T1 is equal to the target ambient temperature w. The actual ambient temperature T1 is then adjusted to match the target ambient temperature w, and the actual ambient temperature T1 is adjusted to match the target temperature T2 of that step-by-step cooling. After the sample is cooled in each step in sequence, it finally reaches the temperature required for cryogenic storage and is stored directly in a liquid nitrogen storage box. The sample cooling and storage method of this invention can simultaneously achieve programmed cooling and sample storage, and is suitable for processing single-layer samples.

Description

[Technical Field]

[0001] This invention relates to a method for storing biological samples, and more particularly to a method for cooling and storing samples. [Background technology]

[0002] To improve the survival rate of cryopreserved cells, it is necessary to gradually lower the temperature to a predetermined level through programmed cooling before storing the cells. Curve A in Figure 1 is a standard ambient cooling curve required for programmed cooling, and curve B is the actual cooling curve of a sample. As can be seen from the figure, the programmed cooling process is divided into multiple stages, so it is necessary to provide multiple independent cooling devices and cool each cell in stages. To achieve the above objective, a Chinese patent, publication number CN 217509762U, discloses a device for programmed cooling of samples. This device connects multiple independent cryogenic storage boxes in series by a transport system, allowing cells to be transferred between multiple cryogenic storage boxes, and cooling each cryogenic storage box to a target temperature at a cooling rate specified according to a programmed cooling stage, ultimately achieving the objective of programmed cooling.

[0003] As can be seen from the above explanation, the programmable cooling system for this sample requires multiple independent cooling units to cool the sample. After cooling, the sample needs to be moved to a separate cryogenic storage unit for storage. While this system is effective when processing large quantities of biological samples, when processing single-layer samples, the separation of programmable cooling and sample storage means that multiple dedicated units are involved in the cooling process, making operation cumbersome, resulting in low convenience and poor effectiveness when processing single-layer samples.

[0004] Therefore, it is necessary to design a programmed cooling and storage method that simultaneously achieves programmed cooling and sample storage, thereby improving the convenience of processing single-layer samples. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] To solve the above problems, the present invention aims to provide a method for cooling and storing samples that can simultaneously perform programmed temperature reduction and sample storage, and that facilitates the processing of single-layer samples. [Means for solving the problem]

[0006] The method for cooling and storing a sample according to the present invention includes the step of placing the sample in a liquid nitrogen storage box, the method for cooling and storing a sample includes raising and lowering the sample within the liquid nitrogen storage box using a lifting device, performing programmed cooling on the sample, and then directly storing the sample in the liquid nitrogen storage box after programmed cooling, and the method for programmed cooling includes the following steps.

[0007] The programmed cooling process is divided into several stage cooling steps that correspond to a standard ambient cooling curve and are executed sequentially, with each stage cooling step including the following steps:

[0008] Step S1: Set the target ambient temperature w in real time according to a standard ambient temperature cooling curve.

[0009] Step S2: Obtain the actual ambient temperature T1.

[0010] Step S3: Compare the target ambient temperature w with the actual ambient temperature T1 and control the raising and lowering of the sample.

[0011] If the target ambient temperature w is higher than the actual ambient temperature T1, the sample is lowered to a predetermined height.

[0012] If the target ambient temperature w is lower than the actual ambient temperature T1, the sample is raised to a predetermined height.

[0013] If the target ambient temperature w is equal to the actual ambient temperature T1, it is determined whether the actual ambient temperature T1 is equal to the target temperature T2 for the step-by-step cooling.

[0014] If the actual ambient temperature T1 at this time is equal to the target temperature T2 for the step-by-step cooling process, the step-by-step cooling process is terminated.

[0015] If the actual ambient temperature T1 at this time is not equal to the target temperature T2 for the step-by-step cooling, steps S1 to S3 are repeated until the actual ambient temperature T1 becomes equal to the target temperature T2 for the step-by-step cooling.

[0016] Furthermore, in the method for cooling and storing a sample according to the present invention, in each stage of the cooling process, the programmable controller controls the output of the servo motor by a PID algorithm, and the calculation adjustment formula for the PID algorithm is as follows. JPEG0003255638000002.jpg14170

[0017] Here, Δy is the output value of the PID algorithm, and K P is the proportional gain, s is the Laplace operator, b is the proportional action weight, w is the set target ambient temperature, x is the actual ambient temperature where the sample is located, and K i is the integral action time, a is the differential delay coefficient, and K d is the differential action time, and c is the differential action weight.

[0018] Furthermore, in the method for cooling and storing a sample according to the present invention, the lifting device is a linear displacement driver driven by a servo motor.

[0019] Furthermore, a method for cooling and storing a sample according to the present invention, wherein the liquid nitrogen storage box is provided in a sample storage device, the sample storage device includes a tank body, a tank lid is provided at the top of the tank body, a rotating frame is provided in the inner cavity of the tank body, the rotating frame includes a housing and a rotating spindle connected to the housing, the bottom end of the rotating spindle is provided on a bearing base at the center of the bottom of the tank body, the top end of the rotating spindle is connected to the output shaft of a rotation driving device through the tank lid, the body of the rotation driving device is fixedly installed on the tank lid, the liquid nitrogen storage box is connected to the housing, a transfer port corresponding to the liquid nitrogen storage box is provided on the surface of the tank lid, and a tank plug is provided at the transfer port.

[0020] Furthermore, a method for cooling and storing a sample according to the present invention, wherein the liquid nitrogen storage box is a rectangular parallelepiped box body with an open top, and a plurality of liquid nitrogen storage boxes are provided around the rotating spindle on the housing.

[0021] Furthermore, a method for cooling and storing a sample according to the present invention, wherein a basket-type sample storage shelf is provided in the liquid nitrogen storage box, the basket-type sample storage shelf is matched with the liquid nitrogen storage box, the basket-type sample storage shelf includes a storage shelf body, a connecting member connected to the output end of a lifting device is provided at the top of the storage shelf body, several layers of storage grooves with open fronts are sequentially provided on the storage shelf body from top to bottom, and single-layer samples are arranged in the storage grooves.

[0022] Furthermore, a method for cooling and storing a sample according to the present invention, wherein in the liquid nitrogen storage box, a point 250 mm from the liquid surface is taken as the origin.

[0023] Furthermore, a method for cooling and storing a sample according to the present invention, wherein the rotation driving device includes a driving motor and a speed reducer, the output shaft of the driving motor is connected to the input shaft of the speed reducer, the output shaft of the speed reducer is connected to the rotating spindle, the speed reducer is a right-angle speed reducer, and its body is fixedly installed on a fixed frame on the surface of the tank lid, and the fixed frame is fixedly installed on the surface of the tank lid.

[0024] Furthermore, a method for cooling and storing a sample according to the present invention is such that bearings are provided between the top end of the rotating spindle and the tank lid, and between the bottom end of the rotating spindle and the bearing pedestal at the bottom of the tank body.

[0025] Furthermore, a method for cooling and storing a sample according to the present invention is such that a rotating tray is further connected to the top end of the output shaft of the speed reducer.

[0026] Furthermore, a method for cooling and storing a sample according to the present invention is such that a shielding sheet is provided on the rotating tray, a vertical plate is provided on one side of the speed reducer, a U-shaped photoelectric switch is provided at the top of the vertical plate, the bottom end of the vertical plate is fixed to the fixed frame, and the shielding sheet can pass through the U-groove of the U-shaped photoelectric switch.

[0027] Furthermore, a method for cooling and storing a sample according to the present invention is such that the housing includes a top frame plate, a bottom frame plate, and several connecting risers connecting the top frame plate and the bottom frame plate. The central part of the top frame plate and the central part of the bottom frame plate are respectively fixedly connected to the rotating spindle.

[0028] Furthermore, a method for cooling and storing a sample according to the present invention is such that the top end of the liquid nitrogen storage box is connected to the edge of the top frame plate via bolts, and a positioning locking groove matching the liquid nitrogen storage box is provided at the edge of the top frame plate.

Advantages of the Invention

[0029] A method for cooling and storing a sample according to the present invention divides the method of programmed cooling into several stepwise cooling methods corresponding to a standard environmental cooling curve. In each stepwise cooling, it is judged whether it is necessary to raise or lower the sample by judging whether the actual environmental temperature T1 is equal to the target environmental temperature w, so as to make the actual environmental temperature T1 coincide with the target environmental temperature w and make the actual environmental temperature T1 coincide with the target temperature T2 of this stepwise cooling. After the sample is cooled in each step in sequence, it finally reaches the temperature required for cryogenic storage and is directly stored in the liquid nitrogen storage box.

[0030] Compared to conventional programmed cooling and sample storage methods, this sample cooling and storage method involves raising and lowering the sample within a liquid nitrogen storage box to perform programmed cooling, and after reaching the cryogenic storage temperature, directly storing the sample in the liquid nitrogen storage box. Since only a single programmed cooling and storage device is involved in the cooling and storage process, it offers extremely high convenience for programmed cooling and storage operations of single-layer samples.

[0031] The above description is merely an outline of the technical concept of the present invention. In order to more clearly understand the technical means of the present invention and to implement it specifically in accordance with the contents of the specification, the present invention will be described in detail below based on embodiments. [Brief explanation of the drawing]

[0032] [Figure 1] These are standard ambient temperature cooling curves and actual temperature cooling curves for samples. [Figure 2] This is an environmental temperature curve diagram showing the temperature from the origin to 600 mm inside a liquid nitrogen storage box. [Figure 3] This is an overall flowchart of the sample program's temperature reduction process. [Figure 4] This is a flowchart of the stepwise cooling process for the sample. [Figure 5] This is a front view of the sample storage device. [Figure 6] This is a cross-sectional view of the sample storage device. [Figure 7] This is a perspective view of the sample storage equipment. [Figure 8] This is a diagram showing the connection between the rotating frame and the rotary drive mechanism. [Figure 9] This is a perspective view of a rotating drive device. [Figure 10] This is a perspective view of a liquid nitrogen storage box. [Figure 11] This is a perspective view of a basket-type sample storage rack. [Figure 12] This is another cross-sectional view of the sample storage device. [Figure 13] This is a diagram showing the connection between the sample storage device and the housing. [Modes for carrying out the invention]

[0033] The following will describe specific embodiments of the present invention in more detail with reference to the drawings and examples. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0034] Referring to Figures 1 to 13, the method for cooling and storing a sample in this embodiment includes the step of placing the sample in a liquid nitrogen storage box, the method for cooling and storing a sample includes raising and lowering the sample within the liquid nitrogen storage box using a lifting device, performing programmed cooling on the sample, and then directly storing the sample in the liquid nitrogen storage box after programmed cooling, and the method for programmed cooling includes the following steps.

[0035] The programmed cooling process is divided into several stage cooling steps that correspond to a standard ambient cooling curve and are executed sequentially, with each stage cooling step including the following steps:

[0036] Step S1: Set the target ambient temperature w in real time according to a standard ambient temperature cooling curve.

[0037] Step S2: Obtain the actual ambient temperature T1.

[0038] Step S3: Compare the target ambient temperature w with the actual ambient temperature T1 and control the raising and lowering of the sample.

[0039] If the target ambient temperature w is higher than the actual ambient temperature T1, the sample is lowered to a predetermined height.

[0040] If the target ambient temperature w is lower than the actual ambient temperature T1, the sample is raised to a predetermined height.

[0041] If the target ambient temperature w is equal to the actual ambient temperature T1, it is determined whether the actual ambient temperature T1 is equal to the target temperature T2 for the step-by-step cooling.

[0042] If the actual ambient temperature T1 at this time is equal to the target temperature T2 for the step-by-step cooling process, the step-by-step cooling process is terminated.

[0043] If the actual ambient temperature T1 at this time is not equal to the target temperature T2 for the step-by-step cooling, steps S1 to S3 are repeated until the actual ambient temperature T1 becomes equal to the target temperature T2 for the step-by-step cooling.

[0044] The present invention provides a method for cooling and storing a sample, wherein the programmed cooling method is divided into several step-by-step cooling methods corresponding to a standard ambient cooling curve, and in each step-by-step cooling, it is determined whether or not the sample needs to be raised or lowered by determining whether or not the actual ambient temperature T1 is equal to the target ambient temperature w, and the actual ambient temperature T1 is made to match the target ambient temperature w, and the actual ambient temperature T1 is made to match the target temperature T2 of the step-by-step cooling. After the sample is cooled in order in each step, it finally reaches the temperature required for storage with the tank lid and is stored directly in the liquid nitrogen storage box.

[0045] Compared to conventional programmed cooling and sample storage methods, this sample cooling and storage method involves raising and lowering the sample within a liquid nitrogen storage box to perform programmed cooling, and after reaching the cryogenic storage temperature, directly storing the sample in the liquid nitrogen storage box. Since only a single programmed cooling and storage device is involved in the cooling and storage process, it offers extremely high convenience for programmed cooling and storage operations of single-layer samples.

[0046] Here, the liquid nitrogen storage box is used to store liquid nitrogen and may be a separate liquid nitrogen storage device or may be provided within a sample storage device.

[0047] In this embodiment, the liquid nitrogen storage box 1 is a rectangular parallelepiped box with an open top and is provided in a sample storage device. The sample storage device includes a tank body 2, a tank lid 3 is provided at the top of the tank body, a rotating frame is provided inside the tank body, the rotating frame includes a housing 4 and a rotating spindle 5 connected to the housing, the bottom end of the rotating spindle is provided on a bearing base 6 in the center of the bottom of the tank body, the top end of the rotating spindle is connected to the output shaft of a rotary drive device through the tank lid, the body of the rotary drive device is fixed to the tank lid, the liquid nitrogen storage box is connected to the housing, a transport port 7 corresponding to the liquid nitrogen storage box is provided on the surface of the tank lid, and a tank plug 8 is provided at the transport port.

[0048] In practice, the enclosure is equipped with multiple liquid nitrogen storage boxes around a rotating spindle. The rotating spindle is driven by a rotation drive device, which rotates the rotating frame, causing the corresponding liquid nitrogen storage box to rotate directly below the transport opening. After this, a lifting device is used to facilitate sample handling.

[0049] To improve insulation, the tank is a double-layered tank, with liquid nitrogen stored inside the tank, and the liquid nitrogen entering the liquid nitrogen storage box via a corresponding passage. Because the cross-section of the liquid nitrogen storage box is smaller than that of the tank, the temperature of the liquid nitrogen inside the storage box is almost the same within the same horizontal plane. On the other hand, due to the large volume of the tank itself, there is a large temperature difference at different locations on the same horizontal plane, making it unsuitable for programmed cooling.

[0050] To perform a lifting operation on single-layer samples, a basket-type sample storage shelf is provided inside the liquid nitrogen storage box. The basket-type sample storage shelf is matched to the liquid nitrogen storage box and includes a storage shelf body 9. A connecting member 10, which is connected to the output terminal of the lifting device, is provided at the top of the storage shelf body. The storage shelf body has several layers of storage grooves 11, which are open at the front end, arranged sequentially from top to bottom, and single-layer samples are placed inside the storage grooves.

[0051] In this embodiment, the origin is set at 250 mm from the liquid surface inside the liquid nitrogen storage box, and Figure 2 shows the ambient temperature curve at 600 mm from the origin. As can be seen from the figure, the change in ambient temperature is small up to 250 mm from the origin, basically remaining below -180°C, and when the position is between 250 mm and 600 mm, the ambient temperature rises from -180°C to 5°C. Here, the position of 600 mm is located at the exit end of the transport port. When the basket-type sample storage rack is lowered to its lowest point, the storage groove of the 22nd layer above it is located at the origin.

[0052] Here, the rotation drive device is used to rotate the rotating spindle, thereby rotating the housing and the liquid nitrogen storage box on it, rotating the corresponding liquid nitrogen storage box directly below the transport opening, and making it easier to operate the basket-type sample storage rack and the samples on it using the lifting device.

[0053] In this embodiment, the rotational drive device includes a drive motor 12 and a reduction gear 13. The output shaft of the drive motor is connected to the input shaft of the reduction gear, and the output shaft of the reduction gear is connected to the rotating spindle. The reduction gear is a right-angle reduction gear, and its body is fixed to a fixed frame 14 on the surface of the tank lid, and the fixed frame is fixed to the surface of the tank lid.

[0054] During operation, the output shaft of the drive motor rotates the reduction motor, which in turn rotates the rotating spindle at the output end of the reduction gear.

[0055] Bearings are provided both between the top of the rotating spindle and the tank lid, and between the bottom of the rotating spindle and the bearing base at the bottom of the tank body, in order to reduce friction.

[0056] A rotating tray 15 is further connected to the top of the output shaft of the gearbox, and a scale is provided on the surface of the rotating tray, making it easy for the operator to observe the position of the rotating frame.

[0057] To achieve positional control of the rotating frame, a shielding sheet 16 is provided on the rotating tray, a vertical plate 17 is provided on one side of the reduction gear, a U-shaped photoelectric switch 18 is provided at the top of the vertical plate, the bottom end of the vertical plate is fixed to a fixed frame, and the shielding sheet can pass through the U-groove of the U-shaped photoelectric switch.

[0058] By providing a U-shaped photoelectric switch and a shielding sheet, the position of the rotating frame can be controlled. Specifically, the rotating tray is driven to rotate on the output shaft of the reduction gear, which in turn rotates the shielding sheet on top of it. When the shielding sheet rotates into the U-groove of the U-shaped photoelectric switch, the optical path of the U-shaped photoelectric switch is shielded, and a corresponding pulse signal is generated. An external control circuit can be controlled to stop the rotation of the drive motor and reduction gear in accordance with this pulse signal and to issue corresponding warning information to alert the operator.

[0059] Preferably, the housing includes a top frame plate 19, a bottom frame plate 20, and several connecting risers 21 connecting the top frame plate and the bottom frame plate, the central portions of the top frame plate and the bottom frame plate being fixedly connected to a rotating spindle, and both the top frame plate and the bottom frame plate being provided with several hollow holes to reduce their weight. The top end of the liquid nitrogen storage box is connected to the edge of the top frame plate via bolts, and the edge of the top frame plate is provided with a positioning locking groove 22 that matches the liquid nitrogen storage box, thereby enabling the liquid nitrogen storage box to be positioned.

[0060] The lifting device is used to drive the sample up and down into the liquid nitrogen storage box, and a corresponding control program enables programmed cooling and storage of the sample.

[0061] In this embodiment, the lifting device is a linear displacement driver driven by a servo motor. The linear displacement driver's body is attached to the output end of a three-dimensional movement mechanism, which is located in a housing 23 above the tank body. A robot is connected to the output end of the linear displacement driver, and the robot corresponds to the connecting member at the top of the basket-type sample storage rack.

[0062] During operation, the three-dimensional movement mechanism moves the lifting device above the transport opening. Next, the linear displacement driver is driven by a servo motor to lower the robot and the basket-type sample storage rack connected to it. After this, the external controller cools and stores the sample according to the programmed cooling method described above. Once storage is complete, each component returns to its original position, preparing for the next operation.

[0063] In this embodiment, based on a standard ambient temperature cooling curve, programmed temperature cooling is performed in five stages, corresponding to the five temperature cooling segments a, b, c, d, and e that approach the straight line of curve A in Figure 1. The temperature control equations for each stage of temperature cooling are as follows. JPEG0003255638000003.jpg7170

[0064] Here, w is the set target ambient temperature, x is the cooling time, k is the cooling rate, and b is the starting temperature of this curve.

[0065] In step S1, the target ambient temperature w is set in real time according to a standard ambient temperature cooling curve. Here, the standard ambient temperature cooling curve is the step-cooling curve corresponding to the step-cooling process and corresponds to the temperature control formula described above. "Real time" here means a short interval, for example, 1 second, which is specifically determined according to requirements such as the accuracy of the system.

[0066] In step S2, the actual ambient temperature T1 can be obtained by installing a temperature sensor at the location where the single-layer sample is located in the basket-type sample storage rack.

[0067] In step S3, the predetermined height at which the sample moves up and down may be a predetermined height set manually, for example, 1 cm, or may be automatically set by the system according to the temperature gradient. Thereby, the sample can reach the actual environmental temperature as soon as possible.

[0068] In step S3, the target temperature T2 of the stepwise temperature reduction, that is, the temperature at the end of the stepwise temperature reduction line segment corresponding to each stepwise temperature reduction in the standard environmental temperature reduction curve.

[0069] In the process of each stepwise temperature reduction, the programmable controller controls the output of the servo motor by the PID algorithm, and the calculation adjustment formula of the PID algorithm is as follows. JPEG0003255638000004.jpg12170

[0070] Here, Δy is the output value of the PID algorithm, K P is the proportional gain, s is the Laplace operator, b is the proportional action weight, w is the set target environmental temperature, x is the actual environmental temperature where the sample is located, K i is the integral action time, a is the differential delay coefficient, K d is the differential action time, and c is the differential action weight.

[0071] Here, K P 、b、K i 、a、K d 、c's specific values may be set by the system according to the accuracy and stability requirements, or may be automatically set.

[0072] The output of the servo motor is controlled by the PID algorithm, whereby the lifting device controls the lifting of the basket-type sample storage shelf and the sample, and the sample can be lifted and lowered accurately, thereby completing the programmed temperature reduction.

[0073] In the PID algorithm, P refers to a proportional regulator, I to an integral regulator, and D to a differential regulator. In a proportional regulator, the adjustment rule is that the controller's output signal u is proportional to the deviation e (deviation e = setpoint w - process value x), and the formula is as follows: JPEG0003255638000005.jpg8170

[0074] In a differential controller, the adjustment rule is that the deviation e (deviation e = setpoint w - process value x) is obtained by the integral action of the integral controller to obtain the controller's output signal u, and the formula is as follows: JPEG0003255638000006.jpg14170

[0075] JPEG0003255638000007.jpg24170JPEG0003255638000008.jpg14170

[0076] JPEG0003255638000009.jpg36170JPEG0003255638000010.jpg15170JPEG0003255638000011.jpg17170

[0077] The PID adjustment formula obtained by differentiating and limiting the above formula is as follows: JPEG0003255638000012.jpg13170

[0078] The above are merely preferred embodiments of the present invention and are used to support those skilled in the art in realizing corresponding technical proposals, but are not intended to limit the scope of protection of the present invention, which is limited to the claims for utility model registration. Furthermore, those skilled in the art can make equivalent improvements and modifications based on the technical proposals of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. At the same time, it should be understood that although this specification has been described based on the above embodiments, each embodiment does not simply contain a single independent technical proposal. This method of explanation in the specification is merely for clarity, and those skilled in the art should consider the specification as a whole, and by appropriately combining the technical proposals of each embodiment, other embodiments that will be understood by those skilled in the art can be formed. [Explanation of symbols]

[0079] 1. Liquid nitrogen storage box 2 Tank bodies 3 Tank lid 4 cabinets 5-rotation spindle 6 Bearing base 7. Conveyor port 8 Tank plugs 9 Storage shelf 10 Connecting members 11 Storage groove 12 Drive motor 13 Reducer 14 Fixed Frame 15 Rotating Trays 16 Shielding sheet 17 vertical boards 18 U-type photoelectric switch 19 Top frame board 20 Bottom frame plate 21 Connection Riser 22 Positioning locking groove 23 Housing

Claims

1. A method for cooling and storing a sample, comprising the step of placing the sample in a liquid nitrogen storage box, wherein the method for cooling and storing a sample involves raising and lowering the sample within the liquid nitrogen storage box using a lifting device, performing programmed cooling on the sample, and directly storing the sample in the liquid nitrogen storage box after programmed cooling, and the method for programmed cooling includes the following steps: Programmed cooling is divided into several step-by-step cooling processes that correspond to a standard ambient cooling curve and are executed sequentially. Step S1 sets the target ambient temperature w in real time according to a standard ambient temperature cooling curve, Actual ambient temperature T １ Step S2 to obtain, Target ambient temperature w and actual ambient temperature T １ By comparing the heights and controlling the raising and lowering of the sample, The target ambient temperature w is equal to the actual ambient temperature T. １ If it is higher than that, lower the sample to the specified height. The target ambient temperature w is equal to the actual ambient temperature T. １ If it is lower than that, raise the sample to the specified height, When the target environmental temperature w is equal to the actual environmental temperature T １ if so, determine whether the actual environmental temperature T １ is equal to the target temperature T of this stage of temperature reduction ２ If the actual environmental temperature T at this time １ is equal to the target temperature T of this stage of temperature reduction ２ if so, step S3 to end the temperature reduction at this stage Includes, The actual ambient temperature at that time was T １ The target temperature T for the stage of temperature reduction. ２ If not equal to the actual ambient temperature T １ The target temperature T for the stage of temperature reduction. ２ A method for cooling and storing a sample, characterized by repeatedly performing steps S1 to S3 until the result is equal to [a certain value].

2. In each stage of the cooling process, the programmable controller uses a PID algorithm. The servo motor output is controlled by the following, and the calculation adjustment formula for the PID algorithm is as follows: Here, Δy is the output value of the PID algorithm, and K Ｐ is the proportional gain, s is the Laplace operator, b is the proportional action weight, w is the set target ambient temperature, x is the actual ambient temperature where the sample is located, and K ｉ is the integral action time, a is the differential delay coefficient, and K ｄ The method for cooling and storing a sample according to claim 1, characterized in that is the differential action time and c is the differential action weight.

3. The method for cooling and storing a sample according to claim 1, characterized in that the lifting device is a linear displacement driver driven by a servo motor.

4. The method for cooling and storing a sample according to claim 3, characterized in that the liquid nitrogen storage box is provided in a sample storage device, the sample storage device includes a tank body, a tank lid is provided at the top of the tank body, a rotating frame is provided in the cavity of the tank body, the rotating frame includes a housing and a rotating spindle connected to the housing, the bottom end of the rotating spindle is provided on a bearing base in the center of the bottom of the tank body, the top end of the rotating spindle is connected to the output shaft of a rotary drive device through the tank lid, the body of the rotary drive device is fixed to the tank lid, the liquid nitrogen storage box is connected to the housing, a transport port corresponding to the liquid nitrogen storage box is provided on the surface of the tank lid, and a tank plug is provided in the transport port.

5. The method for cooling and storing a sample according to claim 4, characterized in that the liquid nitrogen storage box is a rectangular parallelepiped box with an open top, and a plurality of liquid nitrogen storage boxes are provided around a rotating spindle in the housing.

6. The method for cooling and storing a sample according to claim 4, characterized in that a basket-type sample storage shelf is provided inside the liquid nitrogen storage box, the basket-type sample storage shelf is matched to the liquid nitrogen storage box, the basket-type sample storage shelf includes a storage shelf body, a connecting member connected to the output end of a lifting device is provided at the top end of the storage shelf body, several layers of storage grooves with open front ends are provided in order from top to bottom on the storage shelf body, and single-layer samples are placed in the storage grooves.

7. The method for cooling and storing a sample according to claim 4, characterized in that the origin is set at a point 250 mm from the liquid surface inside the liquid nitrogen storage box.

8. The method for cooling and storing a sample according to claim 4, characterized in that the rotating drive device includes a drive motor and a reduction gear, the output shaft of the drive motor is connected to the input shaft of the reduction gear, the output shaft of the reduction gear is connected to the rotating spindle, the reduction gear is a right-angle reduction gear, its body is fixed to a fixed frame on the surface of the tank lid, and the fixed frame is fixed to the surface of the tank lid.

9. The method for cooling and storing a sample according to claim 8, characterized in that a bearing is provided between the top end of the rotating spindle and the tank lid, and between the bottom end of the rotating spindle and the bearing base at the bottom of the tank body.

10. The method for cooling and storing a sample according to claim 8, characterized in that a rotating tray is further connected to the top end of the output shaft of the reduction gear.

11. The method for cooling and storing a sample according to claim 10, characterized in that a shielding sheet is provided on the rotating tray, a vertical plate is provided on one side of the reduction gear, a U-shaped photoelectric switch is provided at the top of the vertical plate, the bottom end of the vertical plate is fixed to a fixed frame, and the shielding sheet can pass through the U-groove of the U-shaped photoelectric switch.

12. The method for cooling and storing a sample according to claim 4, characterized in that the housing includes a top frame plate, a bottom frame plate, and several connecting risers connecting the top frame plate and the bottom frame plate, and the central part of the top frame plate and the central part of the bottom frame plate are fixedly connected to a rotating spindle.

13. The method for cooling and storing a sample according to claim 12, characterized in that the top end of the liquid nitrogen storage box is connected to the edge of the top frame plate via a bolt, and the edge of the top frame plate is provided with a positioning locking groove that matches the liquid nitrogen storage box.

Images